Multiple flexor tendon ruptures due to osteochondroma of the hamate: A case report

Figure 1 Preoperative physical examination. A: The loss of the ring finger flexion involving both proximal and distal interphalangeal joints; B: The loss of the little finger flexion involving both proximal and distal interphalangeal joints.

Figure 2 Flexor tendon continuity of the ring finger and the small finger is not visible in the carpal tunnel on T1 coronal magnetic resonance imaging.

Figure 3 Intraoperative photographs. A and B: Complete rupture of the right ring finger and right small finger flexor tendons (yellow arrows); C: A protruding bony structure like an osteophyte is identified on the side of the hamate in the carpal tunnel, and is covered by cartilage (blue arrow). There is a partial rupture of the right long finger flexor tendon (yellow arrow); D: The intra operative C-arm image shows a bony lesion protruding into the carpal tunnel; E: Excisional biopsy was performed for the bony lesion (yellow arrow); F: Hunter rods were inserted (yellow arrow).

Figure 4 Histopathologic analysis of the hamate bony lesion shows thick cartilaginous tissue, such as the typical cartilaginous cap seen in the common osteochondroma with no malignant changes (hematoxylin-eosin stain, original magnification x 100).